A fuel battery is provided with a stack composed of laminated unit battery cells, each of which is obtained by sandwiching a membrane electrode assembly (MEA) with a pair of separators. An MEA has, for example, a cathode electrode and an anode electrode on both sides of a solid polymer electrolyte film. A fuel battery is, for example, a solid polymer fuel battery provided with a solid polymer electrolyte film. In a solid polymer fuel battery, fuel gas (e.g., hydrogen) supplied to an anode electrode in each unit battery cell of the stack reacts with oxidation gas (e.g., air) supplied to a cathode electrode, so that electric power and water are generated.
Among components of a solid polymer fuel battery, a separator is constituted of a plate member, which is electrically conductive. A flow channel of fuel gas is formed on one outer surface of the separator. A flow channel of oxidation gas is formed on the other outer surface of the separator. Some separators are obtained by constructing one separator from one plate member, while the others are obtained by constructing one separator from two joined plate members. Regarding a separator obtained by two joined plate members, a flow channel of fuel gas is formed on the outer surface of one plate member, and a flow channel of oxidation gas is formed on the outer surface of the other plate member. A flow channel of a cooling medium is formed on the inner surface which lies on the inner side of the two joined plate members.
One of conventional separators obtained by joining two plate members, for example, a separator, which has a structure that two separator plates obtained by processing conductive carbon sheets by cutting work are joined with each other, is disclosed. The two separator plates are respectively provided with a manifold hole, which functions as an inlet of cooling water, and another manifold hole, which functions as an outlet of cooling water. A flow channel of cooling water is formed on the inner surface of the two separator plates. On at least one of the two separator plates, a groove to be filled with sealant is provided at a position surrounding a manifold hole of each of an inlet and an outlet. As the groove is filled with sealant, leakage of cooling water is prevented.
A stack of a solid polymer fuel battery is constructed by laminating a plurality of unit battery cells. The plurality of unit battery cells are tightened in the lamination direction with a plurality of bolts. A conventional separator is composed of two separator plates obtained by processing conductive carbon sheets by cutting work. A conventional separator thus has high rigidity and therefore is unlikely to be deformed by pressure in the lamination direction. Accordingly, a flow channel of cooling water would not be closed by deformation of the separator plates.
However, in a case where a separator is composed of two thin metal plates, it is impossible to obtain high rigidity like a conventional separator. Possible separators composed of two thin metal plates include, for example, a separator which has a convex/concave shape formed by press work, cutting work or the like. The convex/concave shape forms a flow channel of fuel gas or oxidation gas on the outer surface of a thin metal plate, and forms a flow channel of cooling water on the inner surface of a thin metal plate. A separator having such a structure may possibly be deformed by pressure in the lamination direction when a stack is constructed. As the separator is deformed, the distribution channel of cooling water may possibly be closed.
In consideration of the above-described circumstances, it is an object to provide a separator, which can be constructed with two thin metal films and has a distribution channel of a cooling medium that can be maintained if being subject to pressure in the lamination direction.
According to one aspect of the example embodiment, the separator includes: a flat plate-shaped first plate member; a flat plate-shaped second plate member joined with the first plate member; an oxidation gas flow channel wall, which is provided on a first surface of the first plate member and forms a flow channel of oxidation gas; a fuel gas flow channel wall, which is provided on a second surface of the second plate member and forms a flow channel of fuel gas; a cooling medium flow channel wall, which is provided on at least one of a second surface that is a surface on a side opposite to the first surface of the first plate member and faces the second plate member, and a first surface that is a surface on a side opposite to the second surface of the second plate member and faces the first plate member, corresponds to at least one of the oxidation gas flow channel wall and the fuel gas flow channel wall, and forms a flow channel of a cooling medium; a first through hole, which is formed at a position different from the cooling medium flow channel wall and penetrates the first plate member and the second plate member; a second through hole, which is formed at a position different from the cooling medium flow channel wall and from the first through hole and penetrates the first plate member and the second plate member; a first cooling medium passage part, which is formed by separating a part of the second surface of the first plate member and a part of the first surface of the second plate member from each other and establishes communication between the first through hole and one end of the cooling medium flow channel wall; a second cooling medium passage part, which is formed by separating a part of the second surface of the first plate member and a part of the first surface of the second plate member from each other and establishes communication between the second through hole and the other end of the cooling medium flow channel wall; one projection, which is formed on at least one of the first cooling medium passage part and the second cooling medium passage part, is projected from the second surface of the first plate member toward the first surface of the second plate member, and is separated from the cooling medium flow channel wall; and another projection, which is formed at a position corresponding to the one projection on at least one of the first cooling medium passage part and the second cooling medium passage part, is projected from the first surface of the second plate member to the second surface of the first plate member, is separated from the cooling medium flow channel wall, and comes into contact with the one projection in a state where the first plate member and the second plate member are joined with each other.
According to one aspect of the example embodiment, the separator includes: a flat plate-shaped first plate member, which is made of metal; a flat plate-shaped second plate member, which is made of metal and is joined with the first plate member; an oxidation gas flow channel wall, which is provided on a first surface of the first plate member, is projected from the first surface, and forms a flow channel of oxidation gas; a fuel gas flow channel wall, which is provided on a second surface of the second plate member, is projected from the second surface, and forms a flow channel of fuel gas; a cooling medium flow channel wall, which is provided on a second surface that is a surface on a side opposite to the first surface of the first plate member and faces the second plate member as a groove corresponding to the oxidation gas flow channel wall, is provided on a first surface that is a surface on a side opposite to the second surface of the second plate member and faces the first plate member as a groove corresponding to the fuel gas flow channel wall, and forms a flow channel of a cooling medium; a first through hole, which is formed at a position different from the cooling medium flow channel wall and penetrates the first plate member and the second plate member; a second through hole, which is formed at a position different from the cooling medium flow channel wall and from the first through hole and penetrates the first plate member and the second plate member; a first cooling medium passage part, which is formed by separating a part of the second surface of the first plate member and a part of the first surface of the second plate member from each other and establishes communication between the first through hole and one end of the cooling medium flow channel wall; a second cooling medium passage part, which is formed by separating a part of the second surface of the first plate member and a part of the first surface of the second plate member from each other and establishes communication between the second through hole and the other end of the cooling medium flow channel wall; at least one first gasket line, which is a protrusion formed at a position of the first plate member corresponding to at least one of the first cooling medium passage part and the second cooling medium passage part and projected from the first surface of the first plate member; at least one second gasket line, which is a protrusion formed at a position of the second plate member corresponding to at least one of the first cooling medium passage part and the second cooling medium passage part and projected from the second surface of the second plate member; at least one first groove corresponding to the first gasket line formed on the second surface of the first plate member; at least one second groove corresponding to the second gasket line formed on the first surface of the second plate member; and a projection, which is formed on at least one of the first cooling medium passage part and the second cooling medium passage part, is projected from one toward the other of the second surface of the first plate member and the first surface of the second plate member, is extended in a direction crossing at least one of the first groove and the second grove, is formed to be divided into a plurality of parts with at least one of the first groove and the second groove being sandwiched therebetween, and is separated from the cooling medium flow channel wall.
According to one aspect of the example embodiment, the separator includes: a flat plate-shaped first plate member; a flat plate-shaped second plate member joined with the first plate member; an oxidation gas flow channel wall, which is provided on a first surface of the first plate member and forms a flow channel of oxidation gas; a fuel gas flow channel wall, which is provided on a second surface of the second plate member and forms a flow channel of fuel gas; a cooling medium flow channel wall, which is provided on at least one of a second surface that is a surface on a side opposite to the first surface of the first plate member and faces the second plate member and a first surface that is a surface on a side opposite to the second surface of the second plate member and faces the first plate member, corresponds to at least one of the oxidation gas flow channel wall and the fuel gas flow channel wall, and forms a flow channel of a cooling medium; a first through hole, which is formed at a position different from the cooling medium flow channel wall and penetrates the first plate member and the second plate member; a second through hole, which is formed as a position different from the cooling medium flow channel wall and from the first through hole and penetrates the first plate member and the second plate member; a first cooling medium passage part, which is formed by separating a part of the second surface of the first plate member and a part of the first surface of the second plate member from each other and establishes communication between the first through hole and one end of the cooling medium flow channel wall; a second cooling medium passage part, which is formed by separating a part of the second surface of the first plate member and a part of the first surface of the second plate member from each other and establishes communication between the second through hole and the other end of the cooling medium flow channel wall; and a plurality of projections, which are formed side by side in a cross direction to a passage direction of the cooling medium in at least one of the first cooling medium passage part and the second cooling medium passage part, is projected from one toward the other of the second surface of the first plate member and the first surface of the second plate member, and is separated from the cooling medium flow channel wall, wherein an interval between two projections including a center of a width in the cross direction of at least one of the first cooling medium passage part and the second cooling medium passage part is larger than an interval between an end part in the cross direction of at least one of the first cooling medium passage part and the second cooling medium passage part, and a projection adjacent to the end part.
With a separator of the present disclosure, it becomes possible to construct a separator with two thin metal plates and to maintain a distribution channel of a cooling medium if the separator is subject to pressure in the lamination direction.
The above and further objects and features will more fully be apparent from the following detailed description with accompanying drawings.